Step-by-step type pencil



Oct. l0,v 1950 A. P. LYNN s'rEP-BY-STEP TYPE PENCIL Filed April 20, 1945 n m. n w@ Wp my Patented Oct. 10, 1950 UNITED STATES rATENT f OFFICE STEP-BY-STEP TYPE PENCIL Anthony P. Lynn, Elmhurst, Ill.

Application April 2-0, 1945, Serial No. 589,310

10 Claims. (Cl. 120-17) In mechanical pencils much thought has been devoted to the purpose of producing such pencils economically, but with reliable operation. One of the most popular types has been the repeater type pencil, in which the lead is fed by pressing on the top of the pencil. This may also be called a step-by-step type of Vmechanical pencil.

According to the present invention a thorough- 1y reliable repeater type of pencil is provided in which manufacturing costs are extremely low, lower than .the manufacturing costs of such pencils known heretofore.

In addition, a new and simplified form of an adjustable pencil eraser is provided, and also a new, simplified and rugged for-m of clip.

Additional objects and advantages of the invention will become apparent from the following description and from the drawings, in which:

Figure 1 is a longitudinal sectional view of the form of pencil chosen for illustration of this invention; e l

Fig. 2 is a longitudinal sectional view of a somewhat larger scale showing the eraser in a raised position;

Fig. 3 is a fragmentary longitudinal sectional View on a larger scale than Fig. 1;

Fig. 4 is a transverse sectional view taken on line 4 4 of Fig. 3;

` Fig. 5 is afragmentary detailed View of the bayonet clamp for the feed tube;

Fig. 6 is an enlarged face view of the feed tube;

Fig. 7 is an exploded View of the clip and the securing means therefor; and

Fig. 8 is a transverse sectional View taken approximately on line 8-8 of Fig. l.

Although the law requires a full and exact description of at least one form of the invention, such as that which follows, it is, of course, the

purpose ofa patent to cover each new inventive conceptl therein no. matter how it may later be disguised by variations in form or additions of further improvements; and the appended claims are intended to accomplish this purpose by particularly pointing out the parts, improvements, or combinations in which the inventive concepts are found.

, In the form of the `invention chosen for illustration, the pencil includes a barrel I I which may desirably be formed of a plastic. It includes -a large bore I2 communicating at its lower end u of the barrel. This mechanism includes a magazine |6,-a feed tube I1, a clutch housing tube or clutch case I8, and a clutch ring I 9. The inward movement of clutch case I8 into barrel II is limited by engagement of bead 2|] with shoulder I4. The magazine I6` orsome member such as eraser 2| carried thereby, projects from the upper end of the tube and is normally held in this position by spring 22 which is compressed between the magazine and the clutch housing case I8. When the user presses the eraser ZI downwardly, this moves the magazine I6, the feed tube I'I, and the clutch ring I9 downwardly until the clutch I9 strikes shoulder 23 in the clutch case. Furtherpressure on the eraser 2| presses the feed tube II further downwardly until clutch lugs 24 thereon are entirely free of the clutch ring I9 so that the jaws 25 forming the end of the feed tube Il can expand toward the position shown in Fig. 6. This will permit a lead 26 to drop until it engages the tip 2'I of the clutch case.

If a lead is already in place in the tip 2'l`theV downward movement `of the parts will move the lead downwardly through the tip 2l into writing position prior to release of the lead by the expanding jaws 25 at which time the, tip 2l would hold the lead inthis position. The tip 2l is preferably split so as to grip the lead resiliently.

Upon release of the operating pressure from the eraser 2|, the spring 22 raises the magazine I6, the feed tube I1, and the clutch I9. The clutch I9 rides idly above the lugs 24 until the clutch engages a shoulder or constriction 28 in the clutch case I8 at which time the continuing pressure of spring 22 would cause the lugs 24 to be drawn partly into the clutch I9 to clamp the jaws 25 against the lead 2B; thus firmly holding the lead for writing purposes and for feeding on the next operation of 'the mechanism.

Upon the next operation, all of the movable` parts, including the lead 26, move in unison until the clutch I9 again strikes the shoulder 23. Thus the lead would be further advanced by the distance that theclutch I9 reciprocates.

When the feed tube I1 is empty, movement of the parts is limited by the engagement between lugs 3| and slotted washer. 32 which may be sei-V cured atA the upper end of the clutch case IiiV in the manner seen in Fig. 3. The slots 33 in Washer 32 are preferably Vslightly displaced from displacement so that the lugs 3| can only slip past them in one position. The lugs, of course, are correspondingly displaced from 180 separation. The purpose of this is so that it will be extremely rare for the parts to be in such position thatthey will come apart accidentally by passage of the lugs 3I through the slots 33. Of course this would only happen in the rare instances when the parts are in just the right relative position and when there is no lead in the feed tube I1.

If this is found to happen objectionably often, the slots 33 may be slightly undersize so that the lugs 3| can only be drawn therethrough with considerable force. Complete separability of the parts is desirable, however, for the purposes of facilitating repair. The feed tube is secured to the magazine I6 in any suitable manner but is preferably readily removable. At this end the feed tube I1 may be provided with lugs 36 which engage bayonet clamp members 31 formed on a depending portion 38 forming an extension of magazine I6; the bayonet members 31 are preferably provided with humps 39 which tightly engage the lugs 36 as the lugs are turned past them so that once they have been turned past the humps, they will not be accidentally turned to the releasing position. In other words, the bayonet clamp members must be sprung to get the lugs 36 past the humps 39.

Feed tube One of the important features of the invention is the simplicity of the feed tube I1 and the ease with which it may be manufactured.

First a simple straight length of tubing is cut; next the three sets of lugs 24, 3I and 35 are formed thereon simultaneously in a press which merely pinches this metal from the body of the tube by external pressing. Next a simple swaging operation reduces the end of the tube against a threaded mandrel of smaller diameter than the inside of the tube which places threads therein, after which the mandrel is rotated to release it from the threads. The swaging member may be in the form of a collet moving, longitudinally l of the tube and very slightly reducing the diameter at the end of the tube as seen at 42. Next the lower end of the tube is slit with a ne saw which makes a. cut about .010 of an inch to form the slots 4I between jaws 25.

It will usually be desirable to spread the jaws 25 apart so that they will naturally assumey the position shown in Fig. 6 in order to be sure that the threads on the inside of the jaw will give adequate clearance for a lead passing therethrough when the jaws are not clamped against the lead by the clutch ring I9.

The feed tube I1 is now reamed from the upper end to remove any burrs or objectionable ccnstrictions. With these simple operations the feed tube is ready for use.

The lugs 24 should be tapered, lower at their upper ends so as to provide a progressive clamping action as they are drawn into the clutch. 'If their upper edges are. not flush withr the walls of the tube, they should be smoothly rounded toward it so they will not catch on the lower edge of the clutch I9. This permits cutting the clutch square at its lower end, although, of course, it could be internally bevelled if preferred. Preferably the upper end of the clutch is bevelled internally, as seen at Fig. 3, so as to facilitate the insertion of the feed tube I1 therethrough.

Clutch case The clutch case I8 can also be formed economically. It could be drawn from sheet stock or swaged from a tube. In either case a stepped mandrel would be used to produce the shoulder 23 and the converging tip portion. If sheet stock has been used, the next step would be to punch or drill a hole at the tip. Next a slot 44 is cut to provide a resilient gripping of the lead. Next the upper end is shaped to provide annular bead 20 and to receive the washer 32. Thereafter the clutch I9 is inserted and the annular internal bead 28 is formed to limit movement of the clutch. Then the washer 32 is inserted and the ange of tube or case I8 rolled over to maintain the washer in place.

M agaeine The magazine I 6 may also be formed by a simple process. A tube of the full diameter of this magazine would first be swaged at one end or otherwise reduced to provide the sloping portion 46 and the extension 38 of smaller diameter. The bayonet slots would be cut preferably by punching, and a bead 46 (Fig. 1) would be formed to limit the movement of the eraser assembly into the magazine. The sloping portion 46 is inclined approximately as shown so that the leads 26 will have a slight tendency to move toward the tube I1, but not enough to cause jamming. In order that no lead will catch on the upper end of tube I1, it is preferred that a cupped washer 45 be positioned as shown, having a, press fit with the walls of the magazine I6 so as to stay in place.

Eraser assembly The eraser assembly may include, in addition to the eraser 2|, a stirrup 41 by which it is directly carriedand a cup 48 which receives the stirrup 41 and holds itvwith resilient friction.

It is very desirable that some way be provided to adjust the eraser 2I upwardly as it wears down. According to the present invention this is accomplished by the Very simple expedient by providing parallel saw cuts 49 in the wall of cup 48, thus forming deformable bands 5I. There may be two sets of these bands on opposite sides of the cup, or there may be more than two sets equally spaced around the cup. One set would do, but more than one is preferred.

When the eraser has been worn down it may be pushed up in the cup 48 and the bands 5I immediately below its raised position are pressed in with a fingernail, to support the eraser in its new position. A hole 52 is preferably provided in the bottom of cupA 48 so that if the eraser has been worn down too much to be gripped, it may easily be pushed out from the bottom.

Clip

i the clip is first placed within the ferrule 58 with the collars in place within the recesses 59. This assembly is then slipped over the end of the barrel I I. The split collars 56 are shaped to grip the barrel II so as to hold the parts in place. The ferrule 58 prevents their being sprung by a lateral force which they are not well adapted to resist. To apply the assembly t0 the barrel II, the collars 56 may be spread temporarily within the recesses 59 by a suitable spreading tool or mandrel which will hold each collar spread' until 5. it has passed over the end of the barrelll. vIf the barrel is sufliciently rounded or taperedat its end, this will not be necessary. A

.The'partsmay be made of any suitable-materials'. At present brass is preferred for mostof the metal parts,'including magazine I6, 'feed tube l1, clutch case I8 and clutch ring 4I9 because of ease of reshaping, andY resistance to excessive.

corrosion.

From the foregoing it is seen that a pencil is provided which can be manufactured very economically and which is, nevertheless, thoroughly reliable when properly handled. In case improper handling causes a pencil to get out of order, it may easily be taken apart for repairs or replacements.

I claim:

1. A pencil including a magazine, a feed tube secured to and communicating with the magazine, a, clutch case into which the feed tube extends, a -clutch ring slidable within the clutch case and through which the feed tube extends, said feed tube being slotted at its lower end to form jaws and having a plurality of sets of lugs pressed therefrom, one set cooperating with the clutch ring to progressively clamp the jaws of the feed tube against a lead, another set cooperating with the clutch case to limit the movement of the feed tube from the case and another cooperating with securing means on the magazine for securing the feed tube to the magazine.

2. A pencil including a magazine, a feed tube secured to and communicating with the magazine, a clutch case into which the feed tube extends, a clutch ring slidable within the clutch case and through which the feed tube extends, said feed tube being slotted at its lower end to form jaws and having a plurality o-f sets of lugs pressed therefrom, one set cooperating with the clutch ring to progressively clamp the jaws of the feed tube against a lead, and another cooperating with securing means on the magazine for securing the feed tube to the magazine.

3. A pencil including a barrel having a large bore, a smaller bore projecting downwardly therefrom, a clutch case in the small bore and extending from the barrel to form the tip of the pencil and having an enlarged portion limiting the movement thereof into the small bore, a clutch ring slidablypositioned Ain the clutch case, a feed tube extending into the clutch case and into the clutch ring, a magazine carried by the feed tube and communicating therewith and a spring compressed between the magazine and the clutch case, said pencil including means restraining the feed tube within the clutch case to maintain said spring compressed.

4. A clutch assembly for step-by-step type pencils including a clutch case in the form of a tube having a. bore vtherein shaped with portions of larger and smaller diameter and an internally extending bead formed in the tube at a point spaced along the larger bore from the smaller, a clutch ring confined within a larger bore between the smaller and the bead, being longitudinally movable between them, an externally projecting bead forming a shoulder for limiting the movement of the clutch case within a pencil barrel and a slotted retaining member associated with said last named bead and rigid with the clutch case to receive and restrain a feed tube extending into the clutch case.

5. A clutch assembly for step-by-step type pencils including a clutch case in the form of a tube having a stepped bore therein to form bead formed in the tube at a pointy spaced alongthe largerlborefrom the shoulder, a clutch ring conned within .a larger bore between the shouldeand the bead, being longitudinally mov# able between them, an externally projecting bead forming ashoulder .for llimiting the movement of the clutch case within aV pencil'barrel and a retaining member associatedv with said last named bead and rigid with the clutch case to receive and restrain a feed tube extending into the clutch case.

6. The method of forming a feed and clutch tube for step-by-step pencils which includes the steps of pressing the outside walls of a tube to pinch at least one set of externally projecting lugs on the tube, swaging the end of theA tube against a roughened mandrel of smaller diameter than the inside of the tube, and slotting the tube from the swaged end to provide a plurality of jaws each including an internally roughened grip portion and a lug.

'7. A clutch assembly for step-by-step type pencils including a clutch case in the form of a tube having a bore therein shaped with portions of larger and smaller diameter and an internally extending bead formed in the tube at a point spaced along the larger portion from the smaller, Y

a clutch ring confined within the larger portion between the smaller portion and the bead, being longitudinally movable between them, an externally projecting bead forming a shoulder for limiting the movement of the clutch case within a pencil barrel and a slotted retaining member associated with said last-named bead and rigid with the clutch case to receive and restrain a feed tube extending into the clutch case.

8. A clutch assembly for step-by-step type pencils including a clutch case having spaced constrictions, a clutch ring conned within the clutch case and movable longitudinally between said constrictions therein, a slotted retaining member rigidly associated with the clutch case, a feed tube extending through the slotted retaining member and into the clutch ring, said feed tube having lug means thereon engaging the slotted retaining member for restraining the feed tube from movement out of the clutch case except upon a special relationship of the lug means to the slot of the retaining member angularly about a common axis.

9. A feed and clutch tube for step-by-step type Vpencils comprising a, length of tube slotted at one end to form jaws, and a plurality of sets of lugs pressed out from said tube including one set disposed near the ends of said jaws to cooperate with a clutch ring for clamping the jaws against a lead therebetween` another set disposed adjacent the other end of the tube to secure the tubing to a lead magazine, and an intermediate set for limiting the movement of the feed tube within a clutch case.

l0. A feed Vand clutch tube for step-by-step type pencils compris-ing a length of tube slotted at one end to form jaws, and a plurality of sets of lugs pressed out from said tube including one set disposed near the ends of said jaws to cooperate with a clutch ring for clamping the jaws against a lead therebetween, and another `set disposed adjacent the other end of the tube to secure the tubing to a lead magazine.

ANTHONY P. LYNN.

(References on following page) REFERENCES CITED` Number The following references are of record in the le of thls patent. y 211772166 UNITED STATES PA'I'ENTS 5 2,243,109 Number Name Darte 2,287,894

381,612 Bussler Apr. 24, 1888 l 481,462 Benson Aug. 23, 1892 638,962 Frank Dec. 12, 1899 Number Fischer Aug. 24, 1926 10 126,578

8 Name Date -Y Wahl Nov. 2, 1926. Shoemaker Oct. 18, 1927 Stempel Oct. 24, 1939 Lynn May 27, 1941 Lynn June 30, 1942 FOREIGN PATENTS Country Date Germany Jan. 3. 1902 

